How do you judge a singing competition when you don't sing live yourself?
That's the question a lot of "American Idol" fans started asking on Twitter last night during Jennifer Lopez's performance of "I Luh Ya Papi."
While she looked amazing rocking some sparkly Daisy Dukes and dancing up a storm on stage, her vocals took a back seat -- and the lip-sync criticisms started flying online.
To be fair, J.Lo did start out the performance with a lovely a cappella verse, harmonizing with "Idol" alums Pia Toscano, Jessica Sanchez and Allison Iraheta before the backing track took over.
But the haterade began once she started dancing -- and even included a tweet from Travel Channel host Andrew Zimmern.
.@americanidol Did @jlo just lip sync? I am on DVR here. Is this already a "thing" with #idol fans? This is a singing show right?
@andrewzimmern
@MaksimC @JLo what happened to music? People getting ecstatic over a lip sync performance, not even written by the artist... Terrible
@MunkDavid
Nice lipsync #iluhyapapionidol @jlo .. You can sing. . Why fake it like an orgasm? #disappoint
@Kiltmancomics
Yo, JLo. You're a judge on American Idol a LIVE singing competition. Try not to lip sync the next time you perform live. K. Thanks. Bye.
@icediddy
How embarrassing for #jlo that was a terrible lip sync performance. #Americanidol #youretoooldforthatcrap
@twitter_paated
I just got caught up with #AmericanIdol and watched @JLo lipsync to #ILuhYaPapiOnIdol. Why would you do that on a singing show?
@sjiwamiya
That lip synch by J Lo on idol was downright offensive. Not to mention the lyrics were ridiculous. #idol #JLO #lipsync @KidRock
@david4562
What if @JessicaESanchez stole the mic w/ @JLo? "Give me that mic. This is crazy. You are not going to lip sync. Go sit down. Go sit down!"
@NoriJoseph
This jLo performance is really driving home how well Britney Spears can lip-sync
@gatsbygal97
YAAAAS Jenner Lopez! Lip sync FOR YOUR LIFE BITCH!!! #Idol
@IamKingMac
It's common for singers to let a track do the singing while they focus on the choreography -- but what did you think of the performance? Sound off below!